Thallium Stress Test (nuclear stress test)

A thallium stress test (or nuclear stress test) shows the working of the heart muscle. A small amount of radioactive material is injected into a vein and a camera shows how well blood flows to the heart muscle. It's usually done in conjunction with an exercise stress test on a treadmill or bicycle. (Read about "Stress Test")

Holter Monitoring

A Holter monitor is a type of EKG that continuously records your heart's rhythms. The monitor is worn for a period of time, such as 24 hours, while you go about your normal activities.

At the start of the testing time period, electrodes attached to the monitor are connected to your chest. The monitor records your heart's electrical activity during the period of time. Meanwhile, you should be keeping a log of the things you're doing while wearing the monitor. After the period of time is up, you go back to your doctor, who will look at the records and see if there have been any irregular heart rhythms.

30-Day Event Monitor

Event monitors can be similar to Holter monitors, but they are used by patients over a longer period of weeks or months. Electrodes attached to the monitor can be connected to your chest. The monitor is always on but it will record your heart rhythm only when it is activated. The monitor stores the rhythm for review by your doctor. An event monitor can be used to check for irregularities in heart rhythm while you're having symptoms (Read about "Arrhythmia").